The AC in my truck

[Denisefwd93]

Just in case anybody thinks I think, I know a lot about anything I really don't.

My job in HVAC business life was to read everything pertaining to the business. (retired now)

Anyway, I just put dyed PAG and a couple cans of 134 in my own system. I don't expect it to last more than a day or two but I need to get the dye in there and circulating.

Pulled a vacuum on the system, put the end of the low side hose right in the oil bottle, open the valve and watched it draw right into the receiver, being careful not let the hose pull air, an ounce or two was left in the bottom of the oil bottle.

Next ( after hunting down a ACME thread adapter for R134a refrigerant can tap valves) open the valve on the inverted new can on the high side and sent liquid directly in, 12oz cans so probably about 20 oz in there. Started the engine started the AC, surprise surprise surprise (re Gomer) compresser turned on, started pumping started cooling inside the cab! And immediately started short cycling, as I've often mentioned about R134a: after 10 minutes or so it was stabilizing and cutting out on low pressure way way less. The temperature is in the mid-80s today.

Notice I didn't give anybody pressures because they don't really matter at this point but they were in the ballpark for making air conditioning effect.

While looking over the system as it was running, I did notice it was an R12 system changed over to 134 so I guess this truck 1994, was one of those not changed over at the factory.

So, I have a 1994 Ranger with good air conditioning that may or may not have a very large leak!

 

[Denisefwd93]

Day two on checking the air conditioning for leaks nothing showing I probably need to get a better LED flashlight correct?

I'm really not expecting to find any leaks on hoses or connections I've been over them a dozen of times, it's probably the evaporator or the condenser, the evaporator of course being buried within the plastic housing can't even be looked at without taking it apart.

I'm sure it's full of rats nest and other stuff because this truck was a farm truck lol

 

[adsm08]

The evaporator is a pain.

If you get a good humid day, like today, it is often easier to look for dye in the drainage water.

Or get a sniffer and stick it in there.

 

[Denisefwd93]

time to tackle the leak.. the inner fender liner is out so best take advantage of that and pull the ac unit. I think there are some traces of oil on the case

 

[Denisefwd93]

Well, the AC unit has been removed off the firewall! No squirrels in the "squirrel cage" no rats, lots and lots of debris grass and leaves from the critters, not one trace of oil on the evaporator but it needed to come apart anyway. Orifice was funked up,
All's left now is the condenser!

Amazing how much space opens up in the engine compartment by removing the AC unit!

 

[Denisefwd93]

Oh duh! The AC Quick Connect tool is too fat to fit in the ring on the quick connect! Don't you hate that you buy a tool that's made for what it says on the label and it doesn't work?

 

[Denisefwd93]

In the light of day everything looks different the top of the coil is oily seems to be deep inside I didn't see it when I washed it off last night, and said; "we should just put it back in"
I should pressure test it but that means finding some kind of plugs and some kind of way it pressurize it. I think the oil is evidence enough for me to order a new coil, they are under $100 so it'st's not a big expense

 

[Craig0320]

Mine did the same thing. Was leaking at bottom right corner.

 

[Denisefwd93]

It kind of bothers me, being in the AC business most of my life I'm used to cooling and condenser coils lasting almost forever, these things in automotive ac are awful!

Mine did the same thing. Was leaking at bottom right corner.

 

[Craig0320]

Unfortunately not much is made to last anymore. Depending on how pure the metal is in the manufacturing process you might get a great part or not.

 

[wildbill23c]

You charged on the high side for what reason? I was always told to charge from the low side.

Anyhow, repaired the AC in my 88 Bronco last year and its still working LOL. Must mean it don't have any leaks, course I vacuumed the system down and let it set for several hours and never lost vacuum...excellent, replaced the compressor, orifice tube, accumulator, and all the PITA o-rings and recharged the system, I got the AC system flush kit and flushed everything out while I had it all apart and it wasn't very dirty, I was surprised. Got the R134A conversion kit and got everything recharged and was extremely happy as 2 days later it was 102 degrees and I had a working AC in what otherwise is a damn oven.

I didn't pull the cover off the AC Evaporator, maybe I should have but I figured since the system held vacuum it wasn't leaking and was better off leaving well enough alone at that point.

 

[Denisefwd93]

You did a good job!

Vacuum is one of the least reliable ways to find leaks it takes days, hours are not enough actually.

I would also tell you to charge on the low side - cause less damage

charging can be done on the high side with liquid (can upside down) on a non running system, if it's running, you charge on the low side.

R12 & R134a and a few other refrigerants respond quickly to hands or warm water on the can and quickly move the refrigerant into the system and out of the can. Other refrigerants like 410A, need a lot more warmth to force it into the high side but most of it will go into an empty system getting it's initial charge.

 

[Denisefwd93]

It was a beach taking that unit out of there but we got it out removing the hot water lines made it a lot easier also. But looky look at all this space in there!
Seems like a good idea to remove this unit if one is doing an engine swap. Anyhow I rejoined Amazon Prime as a senior for 5.99 a month I'm getting most of my auto parts through there instead of other places because it's free shipping!

 

[planeflyer21]

Geez Denise...I really hope there is supposed to be a decimal in there for that Amazon Prime charge!

That is an amazing amount of space!

 

[Denisefwd93]

Geez Denise...I really hope there is supposed to be a decimal in there for that Amazon Prime charge!

That is an amazing amount of space!

Corrected, thank you!